Service Manual

Usage Information When a UDP broadcast packet is flooded out of an interface, and the outgoing interface is configured using this
command, the outgoing packet’s IP destination address is replaced with the configured broadcast address.
Related Commands
debug ip udp-helper — enables debug and displays the debug information on a console.
show ip udp-helper — displays the configured UDP helpers on all interfaces.
ip udp-helper udp-port
Enable the UDP broadcast feature on an interface either for all UDP ports or a specified list of UDP ports.
Syntax
ip udp-helper udp-port [udp-port-list]
To disable the UDP broadcast on a port, use the no ip udp-helper udp-port [udp-port-list]
command.
Parameters
udp-port-list (OPTIONAL) Enter up to 16 comma-separated UDP port numbers.
NOTE: If you do not use this option, all UDP ports are considered by default.
Defaults none
Command Modes INTERFACE (config-if)
Command History
Version Description
9.9(0.0) Introduced on the FN IOM.
8.3.16.1 Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
If you configure the ip helper-address command and ip udp-helper udp-port command, the
behavior is that the UDP broadcast traffic with port numbers 67/68 is unicast relayed to the DHCP server per the
ip helper-address configuration. This occurs regardless if the ip udp-helper udp-port command
contains port numbers 67/68 or not.
If you only configure the ip udp-helper udp-port command, all the UDP broadcast traffic is flooded,
including ports 67/68 traffic if those ports are part of the udp-port-list.
Related Commands
ip helper-address — configures the destination broadcast or host address for the DHCP server.
debug ip udp-helper — enables debug and displays the debug information on a console.
show ip udp-helper — displays the configured UDP helpers on all interfaces.
show ip udp-helper
Display the configured UDP helpers on all interfaces.
Syntax
show ip udp-helper
Defaults none
Interfaces 559